1. Field of the Invention
The present invention relates to a shock-absorbing structure of a battery cover designed to protect battery electrodes and so on in a battery connecting plate (which serially connects together batteries of a vehicle such as an electric car etc.) at the time of a vehicle collision.
The present application is based on Japanese Patent Application No. 2000-155232, which is incorporated herein by reference.
2. Description of the Related Art
In a power source for a vehicle such as an electric car, a hybrid car (powered by electricity and gasoline), etc., a plurality of batteries are serially connected together to provide a battery block (battery assembly), and then opposite ends of this battery block are covered with covers or the like, and this power source device is mounted within a vehicle body.
FIG. 12 shows one form of a battery connecting plate for connecting a plurality of batteries together.
The battery connecting plates 70 and 71 are attached to opposite ends of a battery block 72, respectively, and each of these battery connecting plates has a plurality of juxtaposed bus bars 75 (made of electrically-conductive metal) mounted on an elongate casing (plate body) 74 made of a synthetic resin.
Each of the bus bars 75 has two insertion holes 78 for respectively passing externally-threaded-type positive and negative electrodes 76 and 77 of the corresponding adjacent batteries 73 therethrough, and these bus bars 75 are fixedly secured to the casing 74 by press-fitting, insert-molding or other ways. Each of the electrodes 76 and 77 is connected and fastened to the bus bar 75 by a nut 79.
Bus bars 83, each having one insertion hole 82, are fixedly secured respectively to opposite ends of the front battery connecting plate 70. The positive electrode 76 of the battery 73, disposed at one end portion of the battery block 72, and the negative electrode 77 of the battery 73, disposed at the other end of the battery block 72, are connected respectively to power wires (not shown), each having a terminal, through the respective bus bars 83.
A cover 80 is pivotably mounted on the casing 74, and when the cover 80 is closed, the bus bars 75 and 83, the electrodes 76 and 77 and the nuts 79 within receiving portions 81 are protected by this cover.
In the above structure, the cover 80 is formed integrally with the casing 74 through hinges. However, as shown in FIG. 13, there is also the case where there are provided a cover 61 and a casing 62 which are separate from each other, and are made of a synthetic resin. In either case, the cover 61, 80 is fixed to the casing 62, 74 by retaining members etc.
In FIG. 13, reference numeral 10 denotes an externally-threaded-type electrode of a battery (not shown), and reference numeral 11 denotes a nut for connecting the electrode 10 to a bus bar or the like.
In the above structure, however, when a large external force b was applied to the cover 61, for example, at the time of a vehicle collision, the cover 61 was broken, and besides an impact was transmitted to the electrodes 10 and bus bars within the casing 62, so that for example as shown in FIG. 14 the distal ends of the electrodes 10 broke through the cover 61 to project to the exterior. This resulted in possibilities that the batteries were short-circuited, which was dangerous, and that the batteries were adversely affected.
In the case of increasing the strength of the cover 61 by increasing the wall thickness of this cover in order to deal with the above problems, the weight of the cover 61 increased, and the resin moldability thereof was affected, and the cost increased. And besides, there was a chance that abnormal sounds were produced because of the increased inertia force of the cover 61 due to vibrations of the vehicle. Furthermore, a large cost was needed for developing a special material of shock-relieving properties, which resulted in a problem that the cost of the cover 61 itself increased.
With the above problems in view, it is an object of the present invention to provide a shock-absorbing structure of a battery cover which can easily and positively absorb and relieve an external impact at low costs, and prevents the projecting of battery electrodes from the cover, and will not adversely affect the parts inside the cover.
To achieve the above object, according to a first aspect of the present invention, there is provided a shock-absorbing structure of a battery cover, which comprises a battery cover which protects at least one battery, and a plurality of shock-absorbing ribs formed on an outer surface of the battery cover.
In accordance with the first aspect of the present invention, the plurality of ribs on the cover are crushed at the time of a vehicle collision, so that an impact is absorbed, and the breakage of the cover except the ribs is prevented. Therefore, the electrodes of the batteries, the bus bars, the terminals and so on within the cover are protected from the external force or impact. Particularly, the externally-threaded-type electrodes of the batteries will not break through the cover, and therefore the short-circuiting of the batteries is avoided. And besides, the plurality of ribs are provided instead of increasing the wall thickness of the cover as in the structure of the related art, and therefore the cover has a lightweight design, and the resin molding of the cover is easy, and the cover is produced at low costs.
According to a second aspect of the present invention, it is preferable that the plurality of ribs are arranged parallel to each other.
In accordance with the second aspect of the present invention, the plurality of ribs are arranged parallel to one another, and therefore an impact is absorbed efficiently, and the transmission of the impact to the parts within the cover is suppressed more effectively.
According to a third aspect of the present invention, it is preferable that the plurality of ribs are crossed in a lattice-like manner.
In accordance with the third aspect of the present invention, an impact, applied in every direction (for example, an impact applied obliquely to the rib), can be efficiently absorbed, and the parts within the cover is more positively protected.
According to a fourth aspect of the present invention, the shock-absorbing structure may further comprise at least one fixing member engaged with an electrode of the at least one battery, and at least one projection which is formed on an inner surface of the battery cover and can abut against the at least one fixing member.
In accordance with the fourth aspect of the present invention, at the time of a vehicle collision, the projection on the cover abuts against the fixing member, mounted on the electrode, and is deformed, that is, bent or crushed, thereby absorbing an impact, so that the electrode is prevented from breaking through the cover. The projections are provided instead of increasing the wall thickness of the cover as in the structure of the related art, and therefore the cover has a lightweight design, and the resin molding of the cover is easy, and the cover is produced at low costs.
Moreover, at the time of a vehicle collision, an impact is more positively absorbed by the synergetic effect of the ribs and the projection, and therefore the protection of the parts within the cover is achieved more positively. The ribs and the projections are formed on the cover, and therefore the cover has a lightweight design as compared with the structure of the related art in which the cover has an increased wall thickness. And besides, the molding of the cover is easy, and the cost of the cover is produced at low costs.
According to a fifth aspect of the present invention, it is preferable that the at least one projection has an annular shape to form a hollow portion therein, and a distal end portion of the electrode is received in the hollow portion of the at least one projection.
In accordance with the fifth aspect of the present invention, a plurality of the projections may have an annular shape, and therefore the projection is spread outwardly or compressed uniformly upon application of an impact, thereby absorbing the impact more efficiently. Therefore, adverse effects on the interior of the cover are further reduced. The distal end portion of the electrode is received in the annular projection, and therefore the protection and insulation of the electrodes are enhanced both before and after a collision.
According to a sixth aspect of the present invention, it is preferable that a gap between the at least one projection and the at least one fixing member is smaller than a gap between the electrode and the battery cover.
In accordance with the sixth aspect of the present invention, the projection first abuts against the fixing member to absorb an impact, so that the distal end of the electrode strikes against the cover with a weakened force, or hardly comes into contact with the cover. Accordingly, the electrode is positively protected, and the electrode is positively prevented from breaking through the cover. Therefore, the short-circuiting at the time of a collision is positively prevented.
According to a seventh aspect of the present invention, it is preferable that the plurality of ribs and the at least one projection are disposed substantially symmetrically with respect to a plane of the battery cover.
In accordance with the seventh aspect of the present invention, at the time of a collision, an impact can be positively absorbed simultaneously by the ribs and the projection, and the protection of the interior of the cover is achieved more positively.
According to an eighth aspect of the present invention, it is preferable that the plurality of ribs are interconnected by at least one bulge portion formed on the battery cover.
In accordance with the eighth aspect of the present invention, the bending strength of the ribs increases, and the ribs will not be bent, but are properly crushed at the time of a collision. Even when an impact is applied in an oblique direction, the ribs will not be bent, but are properly compressed (crushed), and an impact in every direction can be dealt with. The bulge portion is crushed together with the ribs, and therefore the shock-absorbing force is enhanced, and a higher impact can be dealt with.
According to a ninth aspect of the present invention, it is preferable that the at least one bulge portion and the plurality of ribs project substantially to the same height.
In accordance with the ninth aspect of the present invention, the at least one bulge portion can be crushed together with the ribs to absorb the impact more effectively.
Alternatively, to achieve the above object, according to a tenth aspect of the present invention, instead of the first aspect, there may be provided a shock-absorbing structure of a battery cover, which comprises a battery cover which protects at least one battery, at least one fixing member engaged with an electrode of the at least one battery, and at least one projection which is formed on an inner surface of the battery cover and can abut against the at least one fixing member.
In accordance with the tenth aspect of the present invention, similar to the fourth aspect, at the time of a vehicle collision, the projection on the cover abuts against the fixing member, mounted on the electrode, and is deformed, that is, bent or crushed, thereby absorbing an impact, so that the electrode is prevented from breaking through the cover. The projections are provided instead of increasing the wall thickness of the cover as in the structure of the related art, and therefore the cover has a lightweight design, and the resin molding of the cover is easy, and the cover is produced at low costs.
According to an eleventh aspect of the present invention, it is preferable that the at least one projection has an annular shape to form a hollow portion therein, and a distal end portion of the electrode is received in the hollow portion of the at least one projection.
In accordance with the eleventh aspect of the present invention, similar to the fifth aspect, a plurality of the projections may have an annular shape, and therefore the projection is spread outwardly or compressed uniformly upon application of an impact, thereby absorbing the impact more efficiently. Therefore, adverse effects on the interior of the cover are further reduced. The distal end portion of the electrode is received in the annular projection, and therefore the protection and insulation of the electrodes are enhanced both before and after a collision.
According to a twelfth aspect of the present invention, it is preferable that a gap between the at least one projection and the at least one fixing member is smaller than a gap between the electrode and the battery cover.
In accordance with the twelfth aspect of the present invention, similar to the sixth aspect, the projection first abuts against the fixing member to absorb an impact, so that the distal end of the electrode strikes against the cover with a weakened force, or hardly comes into contact with the cover. Accordingly, the electrode is positively protected, and the electrode is positively prevented from breaking through the cover. Therefore, the short-circuiting at the time of a collision is positively prevented.
According to a thirteenth aspect of the present invention, it is preferable that the shock-absorbing structure may further comprise a plurality of shock-absorbing ribs formed on an outer surface of the battery cover.
In accordance with the thirteenth aspect of the present invention, similar to the first aspect, the plurality of ribs on the cover are crushed at the time of a vehicle collision, so that an impact is absorbed, and the breakage of the cover except the ribs is prevented. Therefore, the electrodes of the batteries, the bus bars, the terminals and so on within the cover are protected from the external force or impact. Particularly, the externally-threaded-type electrodes of the batteries will not break through the cover, and therefore the short-circuiting of the batteries is avoided. And besides, the plurality of ribs are provided instead of increasing the wall thickness of the cover as in the structure of the related art, and therefore the cover has a lightweight design, and the resin molding of the cover is easy, and the cover is produced at low costs.
Moreover, at the time of a vehicle collision, an impact is more positively absorbed by the synergetic effect of the ribs and the projection, and therefore the protection of the parts within the cover is achieved more positively. The ribs and the projections are formed on the cover, and therefore the cover has a lightweight design as compared with the structure of the related art in which the cover has an increased wall thickness. And besides, the molding of the cover is easy, and the cost of the cover is produced at low costs.
According to a fourteenth aspect of the present invention, it is preferable that the plurality of ribs are arranged parallel to each other.
In accordance with the fourteenth aspect of the present invention, similar to the second aspect, the plurality of ribs are arranged parallel to one another, and therefore an impact is absorbed efficiently, and the transmission of the impact to the parts within the cover is suppressed more effectively.
According to a fifteenth aspect of the present invention, it is preferable that the plurality of ribs are crossed in a lattice-like manner.
In accordance with the fifteenth aspect of the present invention, similar to the third aspect, an impact, applied in every direction (for example, an impact applied obliquely to the rib), can be efficiently absorbed, and the parts within the cover is more positively protected.
According to a sixteenth aspect of the present invention, it is preferable that the plurality of ribs and the at least one projection are disposed substantially symmetrically with respect to a plane of the battery cover.
In accordance with the sixteenth aspect of the present invention, similar to the seventh aspect, at the time of a collision, an impact can be positively absorbed simultaneously by the ribs and the projection, and the protection of the interior of the cover is achieved more positively.
According to a seventeenth aspect of the present invention, it is preferable that the plurality of ribs are interconnected by at least one bulge portion formed on the battery cover.
In accordance with the seventeenth aspect of the present invention, similar to the eighth aspect, the bending strength of the ribs increases, and the ribs will not be bent, but are properly crushed at the time of a collision. Even when an impact is applied in an oblique direction, the ribs will not be bent, but are properly compressed (crushed), and an impact in every direction can be dealt with. The bulge portion is crushed together with the ribs, and therefore the shock-absorbing force is enhanced, and a higher impact can be dealt with.
According to an eighteenth aspect of the present invention, it is preferable that the at least one bulge portion and the plurality of ribs project substantially to the same height.
In accordance with the eighteenth aspect of the present invention, similar to the ninth aspect, the at least one bulge portion can be crushed together with the ribs to absorb the impact more effectively.